The present invention relates to recycling of plastics and, in particular, it concerns formation of compact repeatable shaped slugs, for recycling or for other use, from PET and other plastic bottles. In the description and claims hereinbelow, the terms “PET bottle” and “plastic bottle” refer to any thermo deformable bottle or container generally designed to be discarded after use. The term “slug”, as used in the description and the claims which follow, generally refers to a compacted/crushed/squashed/chopped plastic bottle. The term “repeatable”, as used in the description and the claims which follow, is intended to mean a result or a product (such as the shape of a slug) that is invariant in its dimensions (for example) within a given tolerance, the tolerance usually equal to a few percentages of the dimensions.
In the “2003 Report on Post Consumer PET Container Recycling Activity”, National Association of PET Container Resources, September 2004, whose disclosure is incorporated herein by reference, it is cited that despite the growing annual rate of usage of plastic drinking bottles (from nearly a million tons of bottles consumed in 1995 to approximately 2 million in 2003), the amount of recycled plastic has not significantly changed in past years and has even declined—from 400,000 tons in 1995 to 350,000 tons in 2002. This data infers an unfortunate negative trend in recycling activities, especially with regard to plastic bottles.
In developed countries protecting the environment by recycling has been defined as a national task. Countries have traditionally committed themselves to specific recycling rate objectives, however the data described hereinabove serves to underscore the need for increased recycling. One way to accomplish this is by the wide scale use of low cost recycling equipment to compact bottles, especially equipment directed for widely distributed home or non-industrial use.
There are number of publications related to plastic bottle compaction equipment which may be directed for home use. The following patent publications, whose disclosure is incorporated herein by reference, cite devices, ostensibly for home or non-industrial use, for squashing and/or crushing plastic bottles:                Metayer, French Patent Application no. 2692190;        Ducreuez, French Patent Application no. 2668732;        Vallee, French Patent Application no. 2712230;        Seidel, German Patent publication no. DE10121599A1;        Montipo, European Patent Application no. EP 149675A2;        Miller, U.S. Pat. No. 6,481,346; and        Lajos Simon, US Patent Application no. 2005/0115420        
Devices illustrated and otherwise described in the French and German applications listed hereinabove apply mechanical force (which, in some cases, is motorized) and apply heat to compress, squash, and otherwise compact a plastic bottle.
Montipo, in European Patent Application no. EP149675A2, discloses a bottle squashing device apparently for table top or counter top use, which employs a pressurized steam supply source to aid in reducing the volume of small disposable containers generally of between 250 and 2000 ml capacity.
The US publications noted hereinabove, by Miller and by Lajos Simon, respectively, disclose devices for application of manual turning power to crush a plastic bottle.
Some of the prior art listed hereinabove describe or otherwise show slugs formed after squashing/crushing/compacting in a substantially axial direction. Although somewhat flattened to an approximate thickness of 2 cm or more, the resultant slugs maintain approximately the initial bottle diameter dimension, and thus the slugs are still relatively large. In general, all of the prior art noted above suffers from the following disadvantages:                a slug is produced that is relatively large, especially in diameter, and of variable shape, making subsequent handling, storage, and recycling of slugs more difficult;        the slug produced is not readily removed from the system, thereby necessitating a possibly cumbersome manual removal process;        the systems do not generally have any controlled way of storing liquids drained from compacted bottles and/or the compacting process; and        there is no integrated storage capability for produced slugs.        
There is therefore a need for a low cost system that can automatically or semi-automatically produce compact and repeatably shaped slugs from compacted plastic bottles, while handling the slugs and liquids from the compacting and slug forming processes in an automated or semi automated fashion.